An inflammatory reaction is a series of processes associated with the elimination of foreign matter and pathogens and the protection and repair of tissue. Excessive inflammatory reactions may cause organ damage and contribute to the occurrence of autoimmune and allergic conditions. It is thought that inflammatory disease, including acute inflammation and chronic inflammation, can be caused by infections and by allergic and autoimmune conditions, but the causes are still poorly understood.
For example, risk factors associated with one inflammatory disease, fulminant hepatitis, include infection by hepatitis viruses (especially the hepatitis B virus), drug allergies, and autoimmune factors, but the mechanism of action is still not understood. At present, liver transplantation is considered to be the most effective treatment for fulminant hepatitis. Other current treatments include steroid pulse treatment and supportive therapy using artificial liver support (Non Patent Literature 1, 2). In recent years, therapeutic effects have been reported from stem cell transplantation in a fulminant hepatitis model (Non Patent Literature 3).
Another inflammatory disease is interstitial pneumonia, which involves chronic and progressive inflammation and fibrosis of the pulmonary interstitia, although the causes are not clear. When the condition progresses to include fibrosis of inflamed tissue, it is called pulmonary fibrosis. One basic therapy is lung transplantation, but therapies using steroids and immune suppressors are common (Non Patent Literature 4). In recent years, therapeutic effects have been reported from stem cell transplantation in a pulmonary fibrosis model (Non Patent Literature 5).
A composition containing culture supernatant of dental pulp stem cells or other stem cells has been described as effective for treating injuries (Patent Literature 1).